c# - how to make changes on an object and its child list property when passing them separately in method? -

i have generic method, takes object , list, list property of object:

public void getsinglelog<tjcls, tlistobj>(int logid, out tjcls log, list<tlistobj> lst) {   var json = (from j in context.tbhistorylog j.id == logid select j.objectjson).first();   var lists = context.tbhistorylog_lists.where(x => x.logid == logid).select(x => x.listjson);   log = audithelper.deserializeobject<tjcls>(json);   foreach (var item in lists)   {     var listjson = audithelper.deserializeobject<list<tlistobj>>(item);     lst.addrange(listjson);   } } 

i call so:

jclstbinventory olog = new jclstbinventory(); ohistory.getsinglelog(logid, out olog, olog.lstdetails); 

the problem log object set, list not. it's returned empty, has data inside getsinglelog.

the dirty workaround approach

this dirty , inefficient (because use expressions , reflection, slow), allow use (bad) model without changes:

public void getsinglelog<tjcls, tlistobj>(int logid, out tjcls log, expression<func<tjcls, list<tlistobj>>> listsetter) {     var json = (from j in context.tbhistorylog j.id == logid select j.objectjson).first();     var lists = context.tbhistorylog_lists.where(x => x.logid == logid).select(x => x.listjson);      log = audithelper.deserializeobject<tlistcontainer>(json);      var list = lists.selectmany(j => audithelper.deserializeobject<list<tlistobj>>(j)).tolist();      var property = (listsetter.body memberexpression)?.member propertyinfo;     if (property == null) throw new exception("expression not reference property");     property.setvalue(log, list, null); } 

which can used this:

jclstbinventory olog; ohistory.getsinglelog(logid, out olog, o => o.lstdetails); 

the inheritance based approach

this approach more reasonable , use inheritance achieving same result, while keeping model consistent.

you need interface this:

public interface ilistcontainer<titem> {     void setlist(list<titem> list); } 

and class want retrieve using method must implement it:

public class jclstbinventory : ilistcontainer<myclass> {     // ... other properties      public list<myclass> lstdetails { get; set; }      public void setlist(list<myclass> list)     {          lstdetails = list;     } 

so may use simpler approach retrieving list:

public tlistcontainer getsinglelog<tlistcontainer, titem>(int id)     tlistcontainer : ilistcontainer<titem> {     var json = (from j in context.tbhistorylog j.id == logid select j.objectjson).first();     var lists = context.tbhistorylog_lists.where(x => x.logid == logid).select(x => x.listjson);      var log = audithelper.deserializeobject<tlistcontainer>(json);      var list = lists.selectmany(j => audithelper.deserializeobject<list<titem>>(j)).tolist();      log.setlist(list);      return log; } 

using way:

var olog = ohistory.getsinglelog<jclstbinventory, myclass>(logid);